main = do
 [a,b] <- map read . words <$> getLine
 print (tri a b)

tri a b
 | a == b = sqrt (a^2 + b^2)
 | otherwise = min x y
 where
  lmin = min a b
  lmax = max a b
  x = sqrt (lmax^2 + lmin^2)
  y = sqrt (lmax^2 - lmin^2)